The official said the police investigation into Flight 370 was officially classified as a criminal investigation on March 15 after government officials announced that the disabling of the communications (ACARS) system and the changing path of the plane were consistent with a deliberate action by someone on the plane.

The official said while at the moment the passengers on MH370 have been "cleared," meaning their background checks have not revealed anything to raise alarm, that does not mean that the focus of the investigation has shifted towards the crew and pilots. According to the official, it means more investigation remains.

According to the official, as part of the investigation, police are also talking to everyone involved in the handling and consignment of the cargo on MH370. The cargo manifest for MH370 has so far not been made public. A request from CBS News for that document is pending.

Two days ago, Malaysia's national police chief Khalid Abu Bakar said that all 227 passengers have been cleared of any involvement, but he admitted that what happened onboard the plane may never be known.

Suspicion has fallen on pilot Zaharie Ahmad Shah and co-pilot Fariq Abdul Hamid, and investigators have now begun interviewing the families of the flight crew.